Worldwide, millions of surface-mounted and pendant-mounted strip fluorescent lighting fixtures have been installed in schools, offices, hospitals, stores and other areas since the 1950's. These fixtures typically include a plurality of fluorescent lamps as well as electromagnetic ballasts, including a transformer and a power capacitor, to control the corresponding lamps.
Since the installation of these fixtures, however, a great number of improvements have been developed in fluorescent lighting technology. As a result, a wide variety of new and highly efficient fluorescent lamps and electronic ballasts are now available. This fact, together with the advancing age of the fluorescent fixtures referenced above, has rendered these lighting fixtures increasingly costly to operate and maintain in comparison to newer model fluorescent lighting fixtures.
One way to reduce the high operating and maintenance costs associated with these older model fluorescent lighting fixtures is simply to replace them with newer, more efficient models. Given the number of fixtures that ordinarily require replacement, however, such a solution can itself be extremely expensive.
Moreover, replacement of the electromagnetic ballasts typically used in the older model fluorescent fixtures can create an additional problem. Many of these ballasts contain materials that can prove difficult and costly to dispose of in view of applicable environmental rules and regulations.
It is well known that the high operating and maintenance costs associated with older model fluorescent lighting fixtures may be reduced through the use of improved reflectors. As exemplified by U.S. Pat. No. 5,062,030 issued to Figueroa and U.S. Pat. No. 4,335,576 issued to Crabtree, fluorescent lighting fixture reflectors have been re-designed such that more light from the fluorescent lamps is directed from the fixture into the workspace. As a result, the number of lamps in the fixture may be reduced without significantly reducing overall illumination from the lighting fixture.
However, such reflector redesign and reduced lamping does not address the problem discussed above regarding the continued operation of inefficient electromagnetic ballasts. Moreover, even with an improved reflector, an older fluorescent lighting fixture may require either the continued use of the less efficient lamps for which it was originally designed, or specially manufactured new lamps. Finally, an improved reflector also does not address the maintenance problems associated with the remainder of the fluorescent lighting fixture, such as louvers, diffusers, lenses, or various mechanical components.
It is also known that costs associated with replacement of older fluorescent lighting fixtures can be reduced through retrofitting. Retrofitting involves replacing only certain parts of an existing fluorescent lighting fixture, while retaining the remainder of the fixture. As is readily apparent, the costs of retrofitting vary depending on the extent of replacement associated with the existing fluorescent lighting fixture. The extent of replacement, in turn, directly affects the extent of savings with respect to future operating and maintenance costs.
A typical fluorescent retrofit unit is shown in U.S. Pat. No. 5,207,504 issued to Swift et al. As disclosed therein, with the exception of the original fixture housing and the fluorescent lamp sockets, the existing lighting fixture is replaced with new components. However, retrofit units such as these also suffer from a variety of problems.
More specifically, such retrofit units can prove both awkward and time consuming to install and inspect. For installation, the existing electromagnetic ballast must be disconnected, removed, and then replaced by an electronic ballast, which itself must then be properly wired to both the fixture power supply and the existing lamp sockets. A lamp cover, reflector and lens must then be separately assembled to the fixture and later removed if proper electrical inspection of the installation has not already taken place.
Moreover, where existing fluorescent lamp sockets are not replaced, the retrofit fixture may again require either the continued use of the less efficient lamps for which those sockets were originally designed, or specially manufactured new lamps. Finally, such retrofit units do not address the previously discussed problem of disposal associated with the removal of existing electromagnetic ballasts.
Thus, an improved retrofit unit for a fluorescent lighting fixture and a method for installing same are needed not only for reducing operating and maintenance costs as well as replacement costs associated with the existing lighting fixture, but also for easing installation and inspection. An improved retrofit unit and method for installing same are also needed to address the problems associated with both the continued operation or disposal of existing fluorescent lighting fixture electromagnetic ballasts.